The recent growth of the consumer wireless communications market has created a need for low-cost, small size parts. A necessary component of many devices is a mixer.
Various configurations of mixer devices are described in an article by Jean-Marc Mourant entitled "A Low cost Mixer for Wireless Applications," 1995 IEEE MTT-S Digest. In particular, at FIGS. 3-5 a mixer utilizing a gate self-biased MESFET configuration is disclosed. As is apparent from the figures, that mixer utilizes a balun to couple the RF signal to the MESFET and includes an LC section which resonates at the RF frequency.
Typically, baluns are difficult to fabricate on integrated circuits and add to the cost and complexity of the circuit. Accordingly, the development of simple, inexpensive mixing circuits is important to reducing cost and complexity of wireless devices.